This invention relates generally to an alarm system for boats and, more particularly, to a system for providing an alarm in response to either boarding of a boat by an intruder or an extensive list that could lead to swamping of a boat.
Theft and general vandalism of moored boats have increased dramatically in recent years. Consequently, boat owners have become increasingly more conscious of the need for effective measures to combat these problems. Protective steps taken have included more extensive use of watchmen and the installation of various types of intrusion alarm systems. The use of watchmen, of course, is a practical solution only for large marinas at which a large number of boats are moored. Conventional alarm and security systems, although generally effective for the protection of large boats, are inappropriate for small boats without fully enclosed cabins, the violation of which is detected by most types of alarm systems. The unauthorized boarding of a small boat could be detected by the so-called tilt alarm, which is used to some extent on automotive vehicles. That alarm comprises a sensor that responds to a change in the vehicle's orientation by initiating an alarm signal. However, use of a tilt alarm on small boats would not be practical because of the false alarms that would result from wave-induced rocking of a floating boat.
The object of this invention, therefore, is to provide a relatively simple device that can reliably detect the unauthorized boarding of small moored boats.